In vivo characterization and analysis of glioblastoma at different stages using multiscale photoacoustic molecular imaging.

Simultaneous spatio-temporal description of tumor microvasculature, blood-brain barrier, and immune activity is pivotal to understanding the evolution mechanisms of highly aggressive glioblastoma, one of the most common primary brain tumors in adults. However, the existing intravital imaging modalities are still difficult to achieve it in one step. Here, we present a dual-scale multi-wavelength photoacoustic imaging approach cooperative with/without unique optical dyes to overcome this dilemma. Label-free photoacoustic imaging depicted the multiple heterogeneous features of neovascularization in tumor progression. In combination with classic Evans blue assay, the microelectromechanical system based photoacoustic microscopy enabled dynamic quantification of BBB dysfunction. Concurrently, using self-fabricated targeted protein probe (αCD11b-HSA@A1094) for tumor-associated myeloid cells, unparalleled imaging contrast of cells infiltration associated with tumor progression was visualized by differential photoacoustic imaging in the second near-infrared window at dual scale. Our photoacoustic imaging approach has great potential for tumor-immune microenvironment visualization to systematically reveal the tumor infiltration, heterogeneity, and metastasis in intracranial tumors.

A microenvironment-responsive FePt probes for imaging-guided Fenton-enhanced radiotherapy of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) continues to be one of the most fatal malignancies with increasing morbidity, and potent therapeutics are urgently required given its insensitivity to traditional treatments. Here, we have developed a microenvironment-responsive FePt probes for the highly efficient Fenton-enhanced radiotherapy (FERT) of HCC. The selective release of Fe2+ in the acidic tumor microenvironment, but not in normal tissue, together with enhanced levels of hydrogen peroxide produced through the Pt radiosensitization effect, facilitates the generation of an enormous amount of hydroxyl radicals through the Fenton reaction, thereby extending the radiotherapeutic cascade and realizing a powerful therapeutic efficacy for HCC. Moreover, the "burst" release of Fe2+ contributes to the T2-to-T1 magnetic resonance imaging (MRI) switching effect, which informs the release of Fe2+, making imaging-guided cancer therapy feasible. This work not only breaks the bottleneck of traditional radiotherapy for HCC while minimally affecting normal tissues, but also provides a new strategy for FERT imaging guidance.

Human Serum Albumin Decorated Indocyanine Green Improves Fluorescence-Guided Resection of Residual Lesions of Breast Cancer in Mice.

OBJECTIVE: Achieving negative resection margin is critical but challenging in breast-conserving surgery. Fluorescence-guided surgery allows the surgeon to visualize the tumor bed in real-time and to facilitate complete resection. We envisioned that intraoperative real-time fluorescence imaging with a human serum albumin decorated indocyanine green probe could enable complete surgical removal of breast cancer in a mouse model. METHODS: We prepared the probe by conjugating indocyanine green (ICG) with human serum albumin (HSA). In vitro uptake of the HSA-ICG probe was compared between human breast cancer cell line MDA-MB-231 and normal breast epithelial cell line MCF 10A. In vivo probe selectivity for tumors was examined in nude mice bearing MDA-MB-231-luc xenografts and the FVB/N-Tg (MMTV-PyMT) 634Mul/J mice model with spontaneous breast cancer. A positive-margin resection mice model bearing MDA-MB-231-luc xenograft was established and the performance of the probe in assisting surgical resection of residual lesions was examined. RESULTS: A significantly stronger fluorescence intensity was detected in MDA-MB-231 cells than MCF 10A cells incubated with HSA-ICG. In vivo fluorescence imaging showed that HSA-ICG had an obvious accumulation at tumor site at 24 h with tumor-to-normal tissue ratio of 8.19 ± 1.30. The same was true in the transgenic mice model. The fluorescence intensity of cancer tissues was higher than that of non-cancer tissues (58.53 ± 18.15 vs 32.88 ± 11.34). During the surgical scenarios, the residual tumors on the surgical bed were invisible with the naked eye, but were detected and resected with negative margin under HSA-ICG guidance in all the mice (8/8). Recurrence rate among mice that underwent resection with HSA-ICG (0/8) was significantly lower than the rates among mice with ICG (4/8), as well as the control group under white light (7/7). CONCLUSIONS: This study suggests that real-time in vivo visualization of breast cancer with an HSA-ICG fluorescent probe facilitates complete surgical resection of breast cancer in a mouse xenograft model.

Photoacoustic molecular imaging-escorted adipose photodynamic-browning synergy for fighting obesity with virus-like complexes.

Photodynamic therapy and adipose browning induction are two promising approaches to reverse obesity. The former strategy acts rapidly and locally, whereas the latter has a more gradual and widespread effect. Despite their complementarity, they have rarely been combined and imaged non-invasively in vivo. Here we introduce an adipose-targeting hepatitis B core protein complex that contains a traceable photosensitizer (ZnPcS4 (zinc phthalocyanine tetrasulfonate)) and a browning agent (rosiglitazone) that allows simultaneous photodynamic and browning treatments, with photoacoustic molecular imaging. After intravenous injection in obese mice, the complex binds specifically to white adipose tissues, especially those rich in blood supply, and drives adipose reduction thanks to the synergy of ZnPcS4 photodynamics and rosiglitazone browning. Using photoacoustic molecular imaging, we could monitor the changes induced by the treatment, which included complex activity, lipid catabolism and angiogenesis. Our findings demonstrate the anti-obesity potential of our feedback-based synergic regimen orchestrated by the targeted hepatitis B core complex.

Near-Infrared Plasmon-Boosted Heat/Oxygen Enrichment for Reversing Rheumatoid Arthritis with Metal/Semiconductor Composites.

Rheumatoid arthritis (RA) is an autoimmune disease that often causes progressive joint dysfunction, even disability and death in severe cases. The radical improvement of inflammatory cell infiltration and the resulting disorder in oxygen supply is a novel therapeutic direction for RA. Herein, a near-infrared-absorbing metal/semiconductor composite, polyethylene glycol-modified ceria-shell-coated gold nanorod (Au@CeO2), is fabricated for topical photothermal/oxygen-enriched combination therapy for RA in a mouse model. Upon laser irradiation, the photothermal conversion of Au@CeO2 is exponentially enhanced by the localized surface plasma resonance-induced light focusing. The elevated temperature can not only remarkably obliterate hyperproliferative inflammatory cells gathered in diseased joints but also vastly increase the catalase-like activity of ceria to accelerate the decomposition of H2O2 to produce much oxygen, which relieves hypoxia. Significantly, RA-induced lesions are improved, and the expression of proinflammatory cytokines and hypoxia-inducible factors is effectively repressed under the cooperation of heat and oxygen. Overall, the core/shell-structured Au@CeO2 is a promising nanotherapeutic platform that can well realize light-driven heat/oxygen enrichment to completely cure RA from the perspective of pathogenesis.

In vivo photoacoustic imaging dynamically monitors the structural and functional changes of ischemic stroke at a very early stage.

Ischemic stroke (IS) is one of the leading causes of death and accounts for 85% of stroke cases. Since the symptoms are not obvious, diagnosis of IS, particularly at an early stage, is a great challenge. Photoacoustic imaging combines high sensitivity of optical imaging and fine resolution of ultrasonography to non-invasively provide structural and functional information of IS. Methods: We adopted three rapid photoacoustic imaging systems with varying characteristics, including a portable handheld photoacoustic system, high-sensitivity bowl-shaped array photoacoustic computed tomography (PACT), and high-resolution photoacoustic microscopy (PAM) to assess the stereoscopic and comprehensive pathophysiological status of IS at an early stage. Two representative models of IS, referring to photothrombosis and middle cerebral artery occlusion (MCAO) models, were established to verify the feasibility of photoacoustic imaging detection. Results: Non-invasive, rapid PACT of the IS model in mouse provided structural information of the brain lesion, achieving early disease identification (5 min after the onset of disease). Moreover, it was able to dynamically reflect disease progression. Quantitative high-resolution PAM allowed observation of pathological changes in the microvascular system of mouse brain. In terms of functional imaging, significant differences in oxygen saturation (sO2) levels between infarcted and normal areas could be observed by PACT, permitting effective functional parameters for the diagnosis of IS. Conclusions: We used PACT to perform full-view structural imaging and functional imaging of sO2 in IS at the macroscopic level, and then observed the microvascular changes in the infarcted area at the microscopic level by using PAM. This work may provide new tools for the early diagnosis of IS and its subsequent complications as well as assessment of disease progression.

High-resolution bimodal imaging and potent antibiotic/photodynamic synergistic therapy for osteomyelitis with a bacterial inflammation-specific versatile agent.

Unsatisfactory diagnosis and therapy of osteomyelitis are still common but challenging issues for clinicians. To overcome these problems, a bacterial inflammation-specific multifunctional agent, denoted bovine serum albumin-manganese dioxide-ubiquicidin29-41-indocyanine green (ICG) -gentamicin (BMUIG), was synthesized for combined high-resolution bimodal imaging and antibiotic/photodynamic therapy for osteomyelitis. BMUIG binding affinity and antibacterial ability were assessed by using Staphylococcus aureus (S. aureus). Photoacoustic/magnetic resonance imaging was performed on a mouse model of acute osteomyelitis after intravenous injection of BMUIG. Then, myelitis-bearing mice were treated with antibiotic/photodynamic combination therapy. BMUIG specifically targeted S. aureus in comparison with non-targeted agents. In the osteomyelitis model, the infection area was identified accurately and quickly through ICG-based photoacoustic imaging and Mn2+-based T1 magnetic resonance imaging after injection of BMUIG. Furthermore, the manganese dioxide in BMUIG reacted with the locally produced hydrogen peroxide under acidic inflammatory conditions, continuously generating oxygen for enhanced photodynamic therapy. In combination with low-dose gentamicin, a synergistic antibacterial effect was observed and bone infection was resolved. In summary, a non-invasive accurate diagnosis and effective synergistic therapy for osteomyelitis was successfully developed using a bacterial inflammation-specific versatile agent, which would provide a sound theranostic strategy for common infectious diseases. STATEMENT OF SIGNIFICANCE: Osteomyelitis is one of the most serious consequences in orthopedics. However, its inaccurate diagnosis and low-effective antibiotic treatment are still common but challenging issues for clinicians. To overcome these problems, we uniquely designed a bacterial inflammation-specific multifunctional nanoagent, bovine serum albumin-manganese dioxide-ubiquicidin29-41-indocyanine green-gentamicin (BMUIG), for high-resolution bimodal imaging and antibiotic/photodynamic combined therapy of osteomyelitis. Herein, high-resolution imaging technologies refer to classic magnetic resonance imaging and emerging photoacoustic imaging. Photodynamic therapy is subtly introduced because of its safe and effective killing mechanism, which can synergize the bactericidal effect of antibiotics. As a result, we successfully realize non-invasive accurate diagnosis and effective synergistic therapy for osteomyelitis by virtue of the bacterial inflammation-specific versatile agent, which will serve as a promising candidate for sound theranostics in common infectious diseases.

In Vivo Quantitative Photoacoustic Diagnosis of Gastric and Intestinal Dysfunctions with a Broad pH-Responsive Sensor.

Gastrointestinal diseases affect many people in the world and significantly impair life quality and burden the healthcare system. The functional parameters of the gastrointestinal tract such as motility and pH can effectively reflect the changes of gastrointestinal activity in physiological and pathological conditions. Thus, a noninvasive method for real-time and quantitative measurement of gastrointestinal functional parameters in vivo is highly desired. At present, there are many strategies widely used for the diagnosis of gastrointestinal diseases in clinic, including X-ray barium meal examination, ultrasound imaging, radionuclide examination, endoscopy, etc. However, these methods are limited in determining the gastrointestinal status and cannot provide comprehensive quantitative information. Photoacoustic imaging (PAI) is a rapid noninvasive real-time imaging technique in which multiple types of functional and quantitative information can be simultaneously obtained. Unfortunately, very few ratiometric PAI contrast agents have been reported for quantification of gastrointestinal functional parameters in vivo. In this work, a broad, pH-responsive ratiometric sensor based on polyaniline and Au triangular nanoplates was developed. Utilizing the sensor as a contrast agent, PAI served as an all-in-one technique, accurately measuring the gastrointestinal functional parameters in a single test. Notably, this sensor was examined to be ultrasensitive with pH responses as fast as 0.6 s and durability as long as 24 h, and was repeatable and reversible for longitudinal monitoring. The quantitative results demonstrated a significant disorder in motility and decrease in pH for gastric and duodenal ulcers. Collectively, the combination of PAI and this broad pH-responsive sensor might be a promising candidate for quantitative diagnosis of gastrointestinal diseases.

Improved Stable Indocyanine Green (ICG)-Mediated Cancer Optotheranostics with Naturalized Hepatitis B Core Particles.

In recent years, hepatitis B core protein virus-like particle (HBc VLP) is an impressive biomaterial, which has attracted considerable attention due to favorable properties such as structural stability, high uptake efficiency, and biocompatibility in biomedical applications. Heretofore, only a few attempts have been made to apply it in physical, chemical, and biological therapy for cancer. In this study, a tumor-targeting RGD-HBc VLP is first fabricated through genetic engineering. For image-guided cancer phototherapy, indocyanine green (ICG) is loaded into RGD-HBc VLP via a disassembly/reassembly pathway and electrostatic attraction with high efficiency. The self-assembled stable RGD-HBc VLP significantly improves body retention (fourfold longer), aqueous stability, and target specificity of ICG. Remarkably, these positive reformations promote more accurate and sensitive imaging of U87MG tumor, as well as prolonged tumor destruction in comparison with free ICG. Moreover, the photothermal and photodynamic effect on tumors are quantitatively differentiated by multiple linear regression analysis. Overall, less-potent medicinal ICG can be perfectly rescued by bioengineered HBc VLP to realize enhanced cancer optotheranostics.

In Vivo Photoacoustic Imaging of Brain Injury and Rehabilitation by High-Efficient Near-Infrared Dye Labeled Mesenchymal Stem Cells with Enhanced Brain Barrier Permeability.

Stem cell migration and interaction with pathology are critical to understand the complexity and status of disease recovery progress. However, the dynamic visualization still remains a great challenge due to imaging technical limitation, cell labeling difficulty, or blood-brain barrier (BBB). Herein, fast photoacoustic tomography (PAT) with optical molecular probes is applied to noninvasively monitor traumatic brain injury (TBI) and its rehabilitation. The vascular distribution and TBI hemorrhage are clearly imaged, longitudinally monitored, and quantified. Bone mesenchymal stem cells (BMSCs) labeled with modified Prussian blue particles (PBPs), excellent near-infrared dyes and photoacoustic contrasts, are intravenously injected to the mice for improved observation and efficient therapy. BMSCs are demonstrated to be capable of overcoming BBB with enhanced delivery of PBPs to the brain parenchyma. Notably, the versatile BMSCs are observed by PAT to home to the damage region and repair the ruptured vasculature. Moreover, the wound treated by BMSCs exhibits much faster recovery speed than that without treatment. These findings can potentially provide a new noninvasive and high-resolution approach to image TBI, monitor recovery process, and especially trace BMSCs. This study will stimulate extensive researches on brain diseases and provide promising strategies of dye labeled BMSCs in regenerative medicine.

Protective Effects of Different Kinds of Filtered Water on Hypertensive Mouse by Suppressing Oxidative Stress and Inflammation.

Oxidative stress and inflammation play an important role in hypertensive animals and patients. Hydrogen plays a role of antioxidation and anti-inflammation. Calcium and magnesium play an important role in reducing hypertension and antioxidant. Filtered water contains abundant hydrogen and a large number of other essential elements of the human body. We investigated the protective effects of filtered water on hypertensive mice. To establish hypertension model, ICR mice were administered with N'-nitro-L-arginine methyl ester (L-NAME) hydrochloride 64 mg/kg per day for 1 month. The hypertensive mice were, respectively, administered with pure water, tap water, and filtered water for 2 months. Lipid peroxidation, antioxidant enzymatic activity, endothelin-1 (ET-1), angiotensin II (Ang II), and proinflammatory cytokines (TNF-α, IL-6, and IL-1ß) were assessed. Expressions of phosphorylated NF-κB P65 in the kidney were analyzed by western blot. qRT-PCR analysis was adopted to determine the expression levels of the proinflammatory cytokines and NF-κB P65. The results demonstrated that filtered water can reduce the blood pressure. Filtered water treatment restored the activity of antioxidant enzymes, downregulated ET-1, and Ang II in the serum of mice. Filtered water treatment suppressed proinflammatory cytokines and decreased the mRNA expression of TNF-α, IL-6, IL-1ß, and NF-κB P65. Consumption of filtered water inhibited the expression of NF-κB P65. This suggests that filtered water can reduce the blood pressure. The protection mechanisms include downregulating oxidative stress and inhibiting inflammation, which is partly due to the inhibition of the NF-κB signaling pathway.

[Effect and mechanism of three kinds of drinking water on blood pressure of hypertensive mice].

OBJECTIVE: To explore the effect of three kinds of drinking water and its possible mechanism on blood pressure of hypertensive mice. METHODS: The water quality parameters were measured for three kinds of drinking water, and the parameters includedtotal dissolved solids( TDS), oxygen consumed( OC), p H, oxidation reduction potential( ORP), electric conductivity( EC), dissolved hydrogen, calcium and magnesium. Establishment of mouse model of high blood pressure by using N'-nitro-L-arginine methyl ester hydrochloride( L-NAME) for 30 days. Then the mice were randomly divided into 4 groups: normal control group, model control group, group of tap water and group of filtered water. Blood pressure in mice was detected every month. After 3 months, nitric oxide( NO), nitric oxide synthase( NOS), total superoxide dismutase( T-SOD), malondialdehyde( MDA), glutathione peroxidase( GSH-Px), endothelin( ET), angiotensin( Ang), aldosterone( ALD), catecholamine( CA), high-sensitivity C-reactive protein( hs-CRP), interleukin 6( IL-6) and cyclic guanosine monophosphate( c-GMP) in serum of the mice were determined. Simultaneously morphological changes of heart, kidney and thoracic aorta paraffin section were observed. RESULTS: The p H, TDS, OC, EC, calcium and magnesium in filtered water were higher than that of pure and tap water. The negative ORP and great quantities of dissolved hydrogen were found in filtered water; The systolic blood pressure and mean blood pressure(( 106. 24 ± 5. 31) and( 90. 73 ± 4. 99)mm Hg) of filtered water were lower than those of the pure water( 119. 58 ± 6. 08 and 96. 44± 6. 48 mm Hg)( P < 0. 05). The NO(( 87. 05 ± 39. 82) µmol/L) in the mice with filtered water were higher than those of with pure and tap water(( 45. 01 ± 9. 62) and( 46. 56 ±30. 54) µmol/L)( P < 0. 05). Compared with those of the mice with pure water, significant decrease in IL-6(( 201. 42 ± 36. 41) and( 173. 99 ± 114. 96) vs. ( 363. 14 ± 149. 00)pg/m L) and Ang(( 1319. 20 ± 111. 90) and( 1349. 38 ± 180. 15) vs. ( 1736. 17 ±242. 86) ng/L) were observed in mice treated with tap and filtered water( P < 0. 05). The T-SOD and GSH-Px(( 268. 37 ± 12. 25) and( 712. 45 ± 30. 59) U/m L) in the mice with filtered water were significant higher than those of pure water(( 250. 46 ± 15. 60) and( 678. 36 ± 35. 80) U/m L)( P < 0. 05). CONCLUSION: Compared with pure and tap water, filtered water can reduce the blood pressure of the hypertensive mice by antioxidation and anti-inflammatory.

[Effect of three kinds of drinking water on learning and memory and hippocampal neurotransmitter of mice].

OBJECTIVE: To explore the effect of three kinds of drinking water on learning and memory and hippocampal neurotransmitter of mice. METHODS: Water quality parameters, including total dissolved solid( TDS), total hardness, oxygen consumed( OC), sodium, potassium, calcium, magnesium and metasilicic acid, were measured for pure water, tap water and natural mineral water. A total of 60 ICR mice( half male and half female) were randomly divided into three groups and fed with pure water( control group), tap water and mineral water for 90 days. After learning-memory abilities were detected with Morris water maze and passive avoidance test, mice were killed and hippocampi were removed immediately to measure contents of acetylcholine( Ach), nitric oxide( NO), glutamic acid( Glu) and gamma-aminobutyric acid( GABA) and activities of acetylcholinesterase( ACh E), choline acetyltransferase( Ch AT) and total nitric oxide synthase( T-NOS). RESULTS: Water quality parameters were higher in tap water and natural mineral water than in pure water. On the first day of place navigation test, the escape latency of tap water group [( 69. 15 ± 50. 87) s]was obviously shorter than that of pure water group [( 86. 07 ± 44. 03) s]( P < 0. 05), and mice in tap water group chose effect strategies( 51. 25%) more frequently compared to control mice( 30%)( P <0. 05). In the probe trial, the swimming time of the targeted quadrant was significantly longer in tap water group [( 28. 44 ± 10. 17) s] or mineral water group [( 28. 81 ±12. 43) s] than in pure water group [( 19. 84 ± 9. 59) s ]( P < 0. 05). In passive avoidance test, the training latency and testing latency were significantly longer in tap water group [( 60. 27 ± 57. 84) and( 209. 54 ± 121. 41) s] or mineral water group[( 58. 12 ± 42. 52) and( 271. 40 ± 90. 44) s]than in pure water group [( 10. 99 ± 9. 40)and( 72. 77 ± 67. 51) s ]( P < 0. 05), as the frequency of electric shock and the percentage of animals showing errors in tap water group [( 0. 90 ± 0. 88) times and 50%]or mineral water group [( 0. 10 ± 0. 32) times and 20%]were obviously less than those in pure water group [( 5. 00 ± 4. 62) times and 90% ]( P < 0. 05). Compared with pure water group [( 8. 53 ± 2. 12) µg / mg prot and( 0. 94 ± 0. 49) U / mg prot], a significant increase of Ach concentration and a significant decrease of ACh E activity were observed in tap water group [( 11. 18 ± 3. 46) µg / mg prot and( 0. 41 ± 0. 21) U / mg prot]or mineral water group [( 12. 91 ± 3. 91) µg / mg prot and( 0. 54 ± 0. 28) U / mg prot]( P < 0. 05). CONCLUSION: Compared with pure water, long-term drinking tap water or mineral water is more beneficial to learning and memory of mice, and it may be associated with a higher content of hippocampal Ach.

[Effect of four kinds of drinking water on hepatic and renal function and zinc and iron concentrations of different organs in mice].

OBJECTIVE: To explore the effect of different drinking water on hepatic and renal function and zinc and iron concentrations of different organs in mice. METHODS: Zinc and iron concentrations were measured in pure water, tap water, mineral water and filtered tap-water, respectively. 80 ICR mice (half male and half female) were randomly divided into four groups and fed with pure water (control group), tap water, mineral water and filtered tap-water, respectively. After 90 days, blood samples were taken from the eyeballs of mice. The contents of serum ALT, TP, BUN, UA and Cr were analyzed. Then mice were killed and livers, kidneys, hearts, pancreas, brains were removed immediately to determinate zinc and iron concentrations. Simultaneously morphological changes of liver and kidney paraffin section were observed. RESULTS: Contents of serum Cr in filtered tapwater group (36. 00 ± 8. 83 µmol/L) were lower than those of pure water group(44. 83 ± 12. 64 µmol/L), tap water group (44. 56 ± 10. 52 µmo/L) and mineral water group (43. 79 ± 10. 53 µmol/L) (P < 0. 05). The zinc concentrations of livers and kidneys (33. 17 ± 6. 18 and 16. 69 ± 8. 12 µg/g) in pure water group was lower than that of filtered tap-water group 45. 31 ± 7. 32 and 22. 61± 6. 01µg/g) P < 0. 05). A significant negative correlation (r = - 0. 300) emerged between the serum Cr and the zinc concentration of kidney in mice P < 0. 05). CONCLUSIONN: Long-term drinking filtered tap-water is beneficial to the glomerular filtration barrier, and it may be related to the increase of zinc levels in kidney.